MathDB
Power×area

Source: Sharygin final round 2017

July 31, 2017
geometry

Problem Statement

ABCDABCD is convex quadrilateral. If WaW_a is product of power of AA about circle BCDBCD and area of triangle BCDBCD. And define Wb,Wc,WdW_b,W_c,W_d similarly.prove Wa+Wb+Wc+Wd=0W_a+W_b+W_c+W_d=0